Transcript Earth*s Motion and Seasons

The Earth and the Universe
Earth’s Motion and Seasons
The goals of this lesson:
I can apply the laws of motion to the
movement of satellites.
I can explain how gravity and inertia
combine to keep objects in orbit.
Flashback Vocabulary
• Gravity- is The attractive force between two
objects.
Gravity also controls the orbits of all the
planets in our solar system as well as our solar
system’s relative motion to the Universe.
* Remember: Gravity is related to the mass of the
objects the more mass the stronger the gravitational
pull.
Newton’s First Law
• An object at rest will remain at rest unless
acted on by an unbalanced force. An object in
motion continues in motion with the same
speed and in the same direction unless acted
upon by an unbalanced force.
This law is often called "the law of inertia".
Newton’s Second Law
• Acceleration is produced when a force acts
on a mass. The greater the mass (of the
object being accelerated) the greater the
amount of force needed (to accelerate the
object).
• Formula F=a(m)
Newton’s Third Law
• For every action there is an equal and
opposite re-action.
The Earth- Vocabulary
• Axis- is the imaginary line from the North Pole
through Earth to the South Pole.
• Rotation- The spinning of the Earth on its axis
causes you to experience day and night.
• Orbit- The Earth moves along a path around
the sun. (elliptical path)
• Revolution- The motion of Earth around the
Sun. (elliptical movement)
How are the Laws of Motion
related to Satellites movement
• Satellites that are launched into space have a
great enough acceleration that the gravity of
the Earth and the fact that the Earth is round
just keeps the Satellite turning around the
Earth in an orbit.
• As the gravity of the Earth try’s to pull the
satellite to the Earth Inertia keeps the Satellite
moving unless something was to get in its
path. (It keeps moving in the same direction)
Earth’s Moon- phases
Earth’s Moon- phases
The goals of this lesson:
I can explain how the position of the sun, moon
and Earth produce moon phases.
I can identify the phases of the moon.
How do moon phases occur
• The Sun is a source of light
the moon gets in
the way causing
a shadow to be
casted on the
Earth.
Moon Phases-Activity
Moon Phases-Eclipses
The goals of this lesson:
I can explain how the position of the sun, moon,
and Earth produce eclipses (solar and lunar).
I can describe a solar eclipse.
I can describe a lunar eclipse.
Vocabulary
• Eclipses- any interference between the light
from the Sun and the object being
illuminated.
(The Moon frequently moves between the Earth
and the Sun, blocking out the Sun’s rays.)
• Solar Eclipse- an event in which the shadow of
the moon falls on the Earth’s surface. (The
moon is between the sun and the Earth)
• Lunar Eclipse- an event in which the shadow
of the Earth falls on the moon. (The Sun is
between the moon and the Earth)
How does an eclipse occur?
Eclipses
• During a Solar Eclipse:
Occurs during a New Moon and cast a shadow
on the Earth
• During a Lunar Eclipse:
Occurs during a Full Moon and the Earth cast a
shadow on the Moon.
Our Solar System
Our Solar System
The goals of this lesson:
I can describe our solar systems place in the
Milky Way Galaxy.
Vocabulary
• Solar System- The system composed of the
sun (a star) and the planets and other bodies
that travel around the sun.
• Galaxy- A large grouping of stars in space.
• Satellite- A natural or artificial body that
revolves around a planet.
• AU (astronomical unit)- The average distance
between the Earth and Sun, or approximately
150,000,000
Milky Way Galaxy
• Our own galaxy consists of about 200 billion
stars, with our own Sun being a fairly typical
specimen. It is a fairly large spiral galaxy and it
has three main components: a disk, in which
the solar system resides, a central bulge at the
core, and an all encompassing halo.
The Earth- Some Facts
Shape: Almost a perfect
Sphere
Mass: 5.98 x 1028 Kg
Average distance from the
sun: 149,600,000 km aprox.
92,584,307.6 miles
Solar day: 24h
Period of revolution (path
around the sun) 1yr- 365
days, 6h, 9 mins.
Sputnick – 1st in Space
• The first satellite in Space
was called Sputnick.
It was a 58cm(23 in) diameter
polished metal sphere, with
four external radio antennae to
broadcast radio pulses. The
Soviet Union launched it into
an elliptical low Earth orbit on
October 4, 1957.
Tides
Tides